Ashley T, Cacheiro N L
Department of Zoology, University of Tennessee, Knoxville 37996.
Cytogenet Cell Genet. 1990;53(4):178-84. doi: 10.1159/000132926.
The meiotic synaptic behavior of male mice heterozygous for one of two X-4 translocations was examined to test a recently advanced hypothesis (Ashley, 1988) suggesting that it is possible to predict the synaptic behavior (nonhomologous vs. homologous) and recombinational parameters (suppression vs. nonsuppression of crossing-over) of a chromosome aberration from mitotic G-band breakpoint data. The hypothesis was based on prior observations of synaptic behavior in a series of X-autosome translocations in mice. The breakpoints of the translocation T(X;4)7R1 are both in G-light bands. As predicted by the hypothesis, synapsis was restricted to homology. In contrast, one breakpoint of the translocation T(X;4)8R1 lies in a "stippled" band of the standard diagrams of Nesbitt and Francke (1981). As predicted (Ashley, 1988), "stippled" bands are shown here to synapse nonhomologously, i.e., they behave as "G-dark." The linkage data, as they relate to the synaptic data and the predictions of the hypothesis, are also discussed.
对两种X-4易位之一的杂合雄性小鼠的减数分裂突触行为进行了检测，以验证最近提出的一个假说（阿什利，1988年），该假说认为，根据有丝分裂G带断点数据，可以预测染色体畸变的突触行为（非同源与同源）和重组参数（交叉抑制与非抑制）。该假说基于之前对小鼠一系列X-常染色体易位突触行为的观察。易位T(X;4)7R1的断点均位于G浅带。正如该假说所预测的，联会仅限于同源性。相比之下，易位T(X;4)8R1的一个断点位于内斯比特和弗兰克（1981年）标准图谱的“点状”带中。正如所预测的（阿什利，1988年），此处显示“点状”带进行非同源联会，即它们表现为“G深带”。还讨论了与突触数据及该假说预测相关的连锁数据。
